o connell



2 Sheets--Sheet 1.

(No Model.)

. J. J. OOONNELL.

METALLIC CIRCUIT TEST AND TIME SIGNAL FOR TELEPHONE EXCHANGES.

1 PatentedJune 9,1891.

-Zzvizwforx 2 Sheets-Sheet 2.

(No Model.)

. J. J. OGONNELL. v METALLIC GIRGUIT TEST AND TIME SIGNAL EoE TELEPHONEEXCHANGES.

No. 454,016. Patented June 9,1891.

T. Wjirwxx as.

Fries,

JOSEPH J. OCONNELL, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE *ESTERNELECTRIC COMPANY, OF SAME PLACE.

METALLIC-CIRCUIT TEST AND TlME-SIGNAL FOR TELEPHONE EXCHANGBSPECIFICATION forming part of Letters PatentNo. 454,016, dated June 9,1891.

My invention relates to telephone-exchange apparatus, and .moreespecially to the system known as the multiple switchrboard I sysr tern.The principal object of my invention is to provide ready means fortesting a line called for at one-board to determine whether said line is'connecteitoriirnse:atany other of the boards.

My invention also includes a time-signaltransmitting device, by means ofwhich any subscriber by simply taking down his telephone andlisteningmay know the time of day.

These results lave been heretofore accomplished in various ways.Myinvention therefore is limited to the apparatus and combinations ofthe devices herein described and claimed.

go I My invention consists, first, in inducing vii bratory currents uponthe metallic circuits by means of a primary Winding upon the cores ofthe individualannunciators, battery, and a rheotome, and preferablyresistance being 3 5 included in the primary circuit, the metalliccircuits being each provided with a single branch circuit to ground atthe subscribers station thereon, The operator at any board; by means ofa telephone included in a ground- 40 circuit,- may by completing thisground-circuit through his telephone, so as to include a portion of anymetallic circuit to be tested, determine whether the linetested is busy.

If the line is in use, the individual annunciator will not be incircuit, and hence there will be no buzz heard in the telephone. If,however, the line is free, a buzz caused by the induced current upon theline will be heard in the telephone. Thus, briefly stated,

the test consists in determining the presence or absence of thevibratory current upon the Applieationfiled October 4, 1.888. 'RenewedApril 18 1891. Serial No. 389,453. (No model.)

thereby operate therelay to shut out for the moment resistance includedin another local circuit containingbattery and a vibrator and convertersfor inducing vibratory currents upon the telephone-lines. The resistancebeing thus removedfrom the local primary circuit at proper times, thestrength of the induced current will be increased at those times, andthe subscriber listening athistelephone and-noting the signals bliLlScaused Will know the time of day.

My time-signal system is especially adapted to be used in connectionwith my test system herein described, since the local primary circuitincluding the primary coils of'the. individual annunciators may beutilized as apart of the time-repeating signal-circuits.

In the accompanying drawings, Figure 1, which is illustrative of myinvention, I have shown threetelephonelines connected each with adiiferent spring-jack switch on each of two multiple switch-boards, thesubscribers apparatus in detail of one of the lines, the testingapparatus at one of the switchboards, the primary circuit, including therheotome, battery, and the extra windings, on the individualannunciators of the three telephone-lines, and the local circuit of arelay, including battery and a, circuit-closer, the relay beingconnected with the primary circuit in such manner as to shut out theresist ance included therein whenever the relay is closed. Fig.2 is avie'willustrative of the manner of operating the local battery-circuit.5

Apparatus adapted to transmit time-signals is also shown more in detailin Letters Patent No. 328,055, granted John M. Oram October 13, 1885.The telephonecircuit a may be traced from ground at the subscrilr looers station thereon through spring jack switch I on the first board, andthence normally through the spring-jack c on the second board, andthence through the secondary winding of the individual annunciator(1,'and thence to the ring or test-piece of each of the 5 switches c b,and thence to the subscribers station and through the generator and bellat like manner connected through spring-jack switches is Z, theindividual annunciator m, and thence to the test-pieces of saidspringjack switches Z k. The local primary circuit 0 includes an extra wnding on each of the annunciators d h m. A rheotome j,included in thiscircuit with battery q, causes a vi- 2o bratory current to becontinuously sent through the primary coils of the annunciators orconverters (Z h m. The resistance '1', included in circuit 0, isdesigned more espe cially as a part of the time-repeating apparatus. Ihave shown the lines a and e looped together by means of loopplugs andcords, the pair of loop-plugs being inserted in springjack switches a gof the lines at thesecond board. When thus inserted, it is evident that,the two lines will be looped together, forming one complete metalliccircuit, while the individual annuneiators d h will be disconnectedtherefrom. When thus disconnected, no current will be induced uponeither of the lines a e from the primary circuit 0. 'At the first boardI have shown a ground-circuit s, in-

eluding a telephone and resistance t, the terminal n of this circuitbeing in the form of a thimble and adapted to be closed upon the 40test-piece or any one of the spring jack switches b f 7c of the firstboard. 1

In order to test any line, it is only necessary to touch the terminal ato the test-piece of the spring-jack of the line and listen at the,-telepl1oneincli1dcdin ground-circuit 3. Thus suppose the operatordesires to test line a.

By simply touching terminal n to the testring of switch b the electricalcondition of line a may be determined by simply listening at thetelephone includedin circuit s. If a plug be inserted in a spring-jackof the line-for example, as shown at switch c-thc converter (1 will beout of circuit and no sound or buzz will be heard. If, however, thelineshould 5;. not be in use, the annunciator (1 would be in circuit, andthe operator listening at the telephone would hear the buzz caused bythe vi bratory current induced on the line through the medium of theannunciator d, acting for the time being as a converter orinductioncoil. Suppose terminal a touching test-ring of switch b, andsuppose the plug removed from switch 0. The circuit then formed would befrom ground atsubscribers stat 'LJll on line a over the limb ofthemetallic circuit a, in-

cluding the spring and contact of each of the switches b c, thencethrourrh Hm snenmlmv taining the annunciator (l.

winding of the annunciator (I, thence to the test-piece of switch I),thence to the terminal nyand thence through circuit 8, including thetelephone; and thence to ground, completing the circuit. Resistance t ispreferbbly in-' cluded in the circuit s, as it is desirable inmetallic-circuit systems to have no more connection with the ground thanis necessary. The operator listening at the telephone under theseconditions will hear the buzz or hum caused by the vibratory currentinduced upon line a through, the medium of the annuneiator-coils of theannunciator d of the line. If a plug be inserted-in any one of thespringjack switches d c of the line, the portion of line a leading tothe subscribers station thereon will beopen to the portion of said linecon- Hence when the test is made no complete circuit will be foundthrough the annunciator (I and no sound will be heard in the telephone.

I will now describe the operation of the timere'peating apparatus. Thearmature-lever of relay 0 is included in a shunt-wire around resistancer. The circuit-closer w is operated in the usual way by clock-work and Iclosed at such intervals as to indicate, for ex ample, the zero-secondof each minute, the minutes, and the hours of the day, forenoon andafternoon, according to any well-known code. I have not deemed itnecessary to show clock-work for doing this work, since for the purposeof illustrating this invention it might be considered as closed by hand.Every time the circuit-closer w is closed the armature-lever of relay '0is operated to close the shunt around resistance r. The resistanceincluded in the local circuit of battery .q'is thus abruptly diminished,thereby abruptly increas ing the current sent through the vibrator p andthe primary coils of the converters. Suppose, then, the plug removedfrom switch cof line a, and suppose the subscriber at the station online a wants-to find out the time. He takes down the telephone, and thetelephone is then in metallic-circuit including the secondary'winding ofconverter (l. Now while the subscriber is listening we will suppose thecircuit-closer w to be closed at the sixtieth second of each minute fora tenth of a second, and then after a space of half a second closed anumber of times corresponding to the hour of the day, and at'tera shortspace a number of times to indicate the minutes. The subscriberlistening at his telephone will hear an increased tone at each closingof the circuit-closer w, and he may thus note the hours, minutes, andseconds, or whatever signal may be indicated.

In Fig. 2 I have illustrated the seconds-hand of a clock connected in alocal circuit cont-aining an elcctro-magnet, the armature of which isconnected with a detent of a circuitcloscr w in such manner that saidcircuitcloser will be actuated to close the local circuit through therelay '0 at the end of each minute. Suitable contact-teeth w, w", and

p w are.provided,which, coming against the contact 1n the local circuit,close the same at intervals determined by the spacing of the .teeth.Tlhe teeth may.-be arranged in the usual manner, so that the hours,minutes, and

seconds'may be indicated. Thus-the teeth I limit myself to theconstruction shown.

. Having thus described my invention, I claim as new and desire tosecureby'Letters Patenting being in acircuit including a battery and 1. Thecombination, with the individual annunciator-of a metallic multipleswitch-board telephone-line circuit, of an extra winding on the core ofsaid annunciator, said extra windrheotome, a telephone included in agroundcircuit havinga terminal adapted to be closed to a test-piece ofthe telephone-circuit, and a ground connection for the telephone-linecircuit at the subscribers station thereon, whereby on closing theterminal of the groundcircuit containing a telephone to the terminal ofthe line the operator listening at the telephone in said ground-circuitmay hear the hum caused by the vibratory current induced upon the line.

2. The combination, with a metallic circuit provided with a groundbranch at the subSGl'LbBliSnstatiom thereon and extendin g through thespring and contact of two or more switches on difierent switch-boards ofa telephone-exchange thro gh the individual annunciator of the line anthence to a testpiece of each of the spring-j ack switches, of

a local battery-circuit including a primary winding provided on the coreof the said'individual annunciator and the rheotome, a ground-circuitproyided with a movable terminal adapted to be closed upon the testpieceof the spring-jack switch, and a telephone included insaid-ground-circuit, whereby enclosing the'termina'l of the ground--circuit to the test-piece of the spring-jack. switch the electricalcondition of the line may be determined,substantially asand for thepurpose specified. 3L The combination, with several metalliccircnittelephone-lines, each including. a different individual annunciator andeach in cluding'a different spring-jack switch on each of two or moremultiple switch-boards, of an extra winding on the individualannunciators, and'an electric circuit common to said extra windings,including a rheotom'e, whereby vibratory currents are induced upon thelines, substantially as and for the purpose spcified.

4. A localpattery-circuit containing a rheotomeaudthe primary coil ofeach of severalconverters, a difierent metallic circuit connectedthrough the secondary coils, respectively, of said converters,telephones, one in each of said metalliccircuits, artificial resistanceincluded in the local battery-circuit, and mechanism adapted to shuntsaid resistance at intervals to indicate the time of day, substantiallyas and for the purpose specified.

5. The combination, with a battery-circuit including a circuit-closerand a relay-coil, of a local primary battery-circuit including arheotome and the primary coils of several converters and resistance, ashunt-wire around said resistance, including the armacure-lever of therelay, metallic circuits, one for each of 'the converters and includingthe secondary coil thereof, andtelephones, one in each of the metalliccircuits, whereby on closingthecircuit-closer the resistance is shuntedout of the local primary battery-circuit to abruptly increase thevibratory current induced upon the metalllc circuits, thereby indicatingto one listening at the telephone in any metallic circuit the time ortimes of the closing of the circuit-closer.

In witnesswhereof I hereunto subscribe my name this30th daylof August,A. D. 1888.

JOSEPH J. OCONNELL. Witnesses;

GEORGE P. BARTON, ELLA EDLER.

